Stabilizing means for schiffli embroidery machines



March 12, 1968 P. F. BOWMAN 3,372,659

STABILIZING MEANS FOR SCHIFFLI EMBROIDERY MACHINES Filed Feb. 15, 1966 2 Sheets-Sheet l I2 INVENTOR ATTORNEYS.

March 12, 1968 P. F. BOWMAN STABILIZING MEANS FOR SCHIFFLI EMBROIDERY MACHINES Filed Feb. 15, 1966 FIG. 3.

2 Sheets-Sheet 2 FIG. 4.

PAUL F. BO M 64.2% M,

GMM

ATTORNEY-S.

United States Patent Ofiiice 3,3'7Z65 9 Patented Mar. 12, 1968 3,372,659 fiTABlLlZlNG MEANS FQR SCHIFFLI EMBROXDERY MACHINES Paul F. Bowman, Ridgewood, N.J., assignor to Joseph L. Schlesinger Incorporated, Ridgefield, N.J., a corporation of New .lersey Filed Feb. 15, 1966, Ser. No. 527,564 9 Claims. (Cl. 1112-91) This invention relates to Schifili embroidery machines and particularly to a new and improved means for stabilizing the frame of a Schiffii embroidery machine.

Schiifli embroidery machines have been known for many years. Such a machine includes a fixed base on which is mounted a horizontally and vertically movable frame. The frame is adapted to support at least one long roll of fabric. Jacquard controlled moving means are employed to move the frame vertically and horizontally relative to the base. Mounted on the base for horizontal reciprocation in a direction perpendicular to the plane of the fabric are a multiplicity of embroidery needles. By moving the fabric relative to the needles as above described and simultaneously operating the needles, a pattern can be embroidered onto the fabric. This pattern is reproduced at each needle or set of needles.

It is quite common that the frame of a Schifili embroidery machine be ten or fifteen yards long. As the movements to the machine are imparted at one end of this long frame structure, the natural elasticity of the frame itself and of its mounting means will cause distortion of the movements at the remote end of the frame which distortion results in a distortion of the pat-tern. This pattern distortion is most pronounced in he vertical direction due to a Whipping action which results in such movement. There is little distortion in the horizontal plane.

Various means have heretofore been suggested for reducing the independent Whip-like movements of the free or remote end of the frame of a Schiffii embroidery machine. Various types of mechanical linkage have been suggested to tie the free end to the driven end, for eX- ample. Such proposals have not proved satisfactory due to the resiliency of the linkage which fails to lock the two ends together for simultaneous movement. Various forms of vibration dampening means have been suggested to reduce the whipping of the free end of the frame. While these have had some beneficial effect, they are not designed to even try to eliminate the distortion at the free end.

The main object of the present invention is to provide means for substantially eliminating the whipping action of the free end of the frame of a Schifili embroidery machine.

Another object of the present invention is the provision of means for locking the free end of the frame of a Schifili embroidery machine to the driven end thereof for simultaneous movement.

Another object of the present invention is the provision of hydraulic means for interconnecting the free and driven ends of the frame of a Schiffli embroidery machine for simultaneous movement.

The above and other objects, characteristics and features of the present invention will be more fully understood from the following description taken in connection with the accompanying illustrative drawings.

In the drawings:

FIG. 1 is a perspective view of a Schifl'li embroidery machine having the present invention incorporated thereon;

FIG. 2 is a diagrammatic view of the machine of FIG.

FIG. 3 is a vertical sectional view of a hydraulic piston and cylinder arrangement for preferred use in the present invention;

FIG. 4 is a top plan view of the piston and cylinder arrangement of FIG. 3; and

FIG. 5 is a sectional View taken along the line 55 of FIG. 3.

Referring now to the drawings in detail and particularly to FIG. 1, a Schifili embroidery machine 10 has a stationary base structure 12 and a horizontally and vertically shiftable frame 14 mounted on the base. Also fixed to the base 12 is a jacquard control mechanism 16 which controls the moving means 17 that imparts the horizontal and vertical movements to the frame 1-4. As shown, there are mounted on the frame two lengths of goods 18 and 20 which are to be embroidered by two groups of embroidery needles 22 and 24 which operate in unison in a horizontal reciprocal motion for stitching thread associated therewith. The pattern to be embroidered is determined by the movements of the frame 14 which moves the two lengths of fabric 18 and 20 mounted thereon. By combining horizontal and vertical movements to the frame and hence to the goods, various patterns will be stitched by the needles 22 and 24 onto the fabric 18 and 20, respectively.

The output from the jacquard control mechanism 16 controls moving means 17 which are connected to the left-hand or driven end 26 of the frame 14 for moving the frame vertically and horizontally as above described. As mentioned in the introduction of this description, the entire frame 14 is supposed to move in unison whereby to give a unified pattern at each needle station on both levels of fabric. However, and as already noted, due to the inherent resiliency of the frame 14 and of its mounting means, there is a tendency for the free end 28 of the frame to Whip, especially in the vertical direction, whereby to give a substantially distorted pattern on the fabric adjacent the right hand or free end 23. It is this whipping in the vertical direction of the free end 28 of frame 14 that the present invention is designed to eliminate. While the above description of the Schiffii machine is broad and general, the structure itself is old and well known and requires no more detailed description for an understanding of the present invention.

Referring now to FIG. 2, the means for eliminating the whipping of free end 28 of frame 14 is shown in a schematic drawing. This stabilizing means or control system 30 embodying the present invention includes two piston and cylinders 32 and 34 with interconnecting pipelines 36 and 38. Particularly, the piston-cylinder 32 includes a cylinder 40 which is connected by a suitable rigid connecting means such as cage 42 to the base 12 adjacent the driven or left end 26 of frame 14. Slideably disposed with in the cylinder 40 is a piston 44, the piston rod 4-6 of which is connected to the frame 14 of the machine 10. Thus the piston 44 Will move relative to the cylinder 40 in accordance with the vertical inputs from the jacquard controlled moving means 17 to the left-hand or connected end 26 of frame 14.

The piston and cylinder 34 at the right-hand or free end of the frame 14 includes a cylinder 48 which is con nected by a suitable rigid connecting means 50 to the base 12. Slideably disposed Within the cylinder 48 is a piston 52 which is connected to a piston rod 54 that is in turn conected to the right-hand or free end 28 of the frame 14. The pipeline 36 extends from the cylinder 40 above the piston 44 to the cylinder 48 below the piston 52. The pipeline 38 extends from the cylinder 40 below the piston 44 to the cylinder 48 above the piston 52. All of the void space within the control system 30, that is the spaces in the cylinders 40 and 48 above and below the pistons 44 and 52, respectively, as well as the pipelines 36 and 38 are filled with an incompressible fluid such as a hydraulic oil or the like. A fluid makeup means 53 of conventional design is included to make up lost oil resulting from leakage or the like.

Assuming substantially perfect incompressibility of the fluid medium within the control system 30, when the frame 14 is moved downwardly in response to the operation of the jacquard mechanism 16, the piston 44 will move downwardly relative to the cylinder 40. This will cause an expansion of the volume of the cylinder 40 above the piston 44 and a reduction of the volume of the space in cylinder 40 below piston 44. Since the fluid within the piston and cylinder 32 is incompressible some of the fluid within the space in cylinder 40 below piston 44 will be forced out of that space and into the pipeline 38 connected therewith. The incompressibility of the fluid within the system will cause a displacement of fluid in pipeline 38 and hence an increase in the volume of the fluid in cylinder 43 above piston 52. This increase will be identical to the decrease in volume of that portion of the cylinder 40 below the piston 44. The increase in the volume of cylinder 48 above piston 52 will cause a downward displacement of the piston 52 identical with the downward movement of the piston 44 that initiated the chain of events. This downward movement of the piston 52 will move the free end 28 of the frame 14 downward the same distance as the driven end 26 of the frame 14 has been moved downward by the input mechanism of the jacquard control system. Thus the free end 28 will be driven substantially identically with the driven end 26 of the frame 14.

Upon the piston 52 moving downwardly in the cylinder 48, there will be a displacement of fluid out of the cylinder 48 from the space below the piston 52 which fluid will be displaced into the pipeline 36. Likewise within the pipelne 36 there will be displacement at the other end thereof out of the pipeline 36 and into the space in the cylinder 40 above the piston 44. This displacement will be identical to the amount of space made available by the original downward movement of the piston 44 relative to the cylinder 49. Thus upon the driven end 26 being moved downwardly by the jacquard controlled moving means 17, through the displacement piston cylinder arrangement described, the free end 28 will move downwardly a substantially identical vertical distance.

It will be obvious to anyone skilled in the art that upon the driving means 17 forcing the driven end 26 upwardly, a substantially reverse sequence of events will occur to force the piston 52 upwardly relative to cylinder 48 and thereby move the free end 28 of frame 14 upwardly a distance substantially identical to the distance of upward movement of the driven end 26 of the frame. In this manner the free end is in effect converted into a second driven end which is driven substantially identically with the driven end 26 whereby to eliminate the whipping distortions in the movement of the free end 28 of frame 14 and the resultant distortions in the patterns formed on the fabric mounted on or near that free end of the frame. While there might be some vibrational distortions still present in the center of the frame 14, in view of the fixing of the free end 28 relative to the driven end 26, which in effect converts the frame from a cantilever into a simple beam, and further in view of the fact that the distance between the two ends of the frame and the middle is onehalf of the distance between the two ends themselves, the amount of vibrational distortion encountered in the middle of the frame 14 will be an almost insignificant fraction of the distortion previously encountered at the free end of a conventional Schiflli machine without the control means 30 heretofore described.

It will be noted that the piston and cylinder 32 has the cylinder 40 with its blind end up and its gland end down, whereas the piston and cylinder 34 has the blind end down and the gland end up. This arrangement is desirable for connecting those portions of the cylinders 44} and 48 through which the piston rods extend and to connect the other portions of the cylinders to each other. If a reverse orientation of the piston and cylinder 34 relative to the piston and cylinder 32 were employed, the system would not operate properly due to the presence of the piston rods 46 and 54 which significantly change the volume of that portion of the cylinder chamber surrounding them. For example, if both piston and cylinder arrangements 32 and 34 were similarly oriented, when the piston 44 moved, for example, a /2, the volume of fluid displaced by that /2" movement would be equal to the area of the piston minus the area of the piston rod times /2". Such a volumetric displacement of incompressible fluid if it were fed into the cylinder volum not encircling the piston rod 54 would result in a displacement of the piston which would be less than /2", thereby resulting in distortion. By connecting the piston rod sides of both cylinders together and the non-piston rod sides of both cylinders together and reversing the orientation of one piston and cylinder with respect to the other piston and cylinder, this distortion is eliminated to insure a substantially identical displacement of both pistons and cylinders 32 and 34. Another means of compensating for the volume of the piston rods is to provide false piston rods on the blind ends of the pistons fixed to the pistons and slidably mounted in the gland ends of the cylinders.

It will be obvious that the control system 36) will operate if the components are all reversed 180. For example, the piston and cylinder 32 could extend downwardly from the frame with the piston rod connected to the frame and the cylinder connected to the base 12 provided the piston and cylinder 34 extended upwardly of the frame using a mounting means similar to the means 42 with the piston rod connected to the frame and the cylinder connected through the connecting means 42 to the base 12. The pipeline connections would remain identical. Other equivalent constructions to tie two pistons and cylinders to each other will now become readily apparent to anyone skilled in the art.

It has already been noted that the fluid filling up all voids within the system 30 must be incompressible. As previously noted a low viscosity hydraulic fluid is preferred, although if problems of corrosion and the like are reduced by a proper selection of materials even water would be an excellent fluid medium. However, there can be substantially no compressible fluid present in the system if the system is to work satisfactorily. That is to say, for example, if an air bubble of significant proportion were trapped in the system, when there was displacement of the piston on the driven end of the frame, which displacement will cause a shifting of hydraulic fluid, that shifting may be substantially absorbed by an air bubble in its own compression. Thus, it is vital in the present system to provide means for removing any trapped air or other gas from the liquid filling the control system 30.

A preferred piston and cylinder structure for the present system 30 is illustrated in FIGS. 3, 4 and 5. Referring now to these figures, a cylinder 48 of circular cross-section is shown in which a piston 44 is slideably disposed. The cylinder 40 includes a central hollow cylindrical portion 60 having a blind end body 62 overlying and closing off the upper end thereof and a gland end body 64 overlying and closing off the bottom end thereof. The blind end body 62 has a lower cylindrical portion 66 that is press fitted into the upper end of cylinder 60 and is sealed thereto as by an O-ring 63, Extending up from the very bottom of the blind end body is a cylindrical cavity 70 from which extends two passages, one of substantially large diameter with a threaded wall therein designated by the reference numeral 72, and the other of slightly smaller diameter and also provided with a threaded wall therein and designated by the reference numeral 74. The passage 72 is for connection to one of the conduits or pipelines 36 and the passage 74 is for connection to a pressure gauge, if desired. In the alternative and as shown, the passage 74 can be plugged by a suitable plug 75 which will seal off the passage 74. At the upper end of the cavity 70 there is a conical portion 76 the top of which leads into a narrow air bleed passage 78 which is in communication with a threaded outlet 80 normally closed by a threaded plug 82. Overlying the top of the blind end body 62 is an end cap 84.

The bottom of the central cylindrical portion 60, as already noted, is closed by a gland end body 64. Gland end body 64 has a portion of reduced cross-section at the top thereof which is press fitted into the bottom of cylinder 60. This portion is designated by the reference numeral 86 and is sealed to the interior of the cylinder wall as by an O-ring 88. Extending down from the cylinder cavity and in communication therewith is a gland end cavity 00 from which extends a threaded hydraulic fluid outlet 92 adapted to be connected to the pipeline 38, a threaded outlet 94 which is adapted to be connected to a pressure gauge (not shown) or which may be plugged by a threaded plug 96 to thereby seal it off, an air bleed passage 98 which extends in from the bland end body cavity 90 adjacent the bottom thereof and to an enlarged outlet 100, here shown as being sealed by a threaded plug 102. The central cavity or passage 90 in the gland end body adjacent the bottom is enlarged to accommodate U-cup pedestal 104 which is sealed to the gland end body wall by an O-ring 106. A piston rod 108 extending from the piston 44 down and out through the cylinder structure 40 passes through the pedestal 104 with clearance to provide an air passage. At a plurality of places distributed along the pedestal 104, here shown as four in number, are a plurality of longitudinally extending air passages 110 to provide an air passage communication between the cavity 90 and the air bleed passage 98 for reasons which will become apparent hereinafter.

Below the U-cup pedestal 104 is a U-cup 109 of annular configuration which is adapted to provide a sliding seal between the gland end body 64 and the piston rod 168. Below the U-cup 109 is a bearing 112 in sliding supporting relation with piston rod 108. Bearing 112 is disposed in an opening 113 of the upper portion 115 of the gland end cap. The lower portion of the gland end cap, herein designated by the reference numeral 114, is provided with a central opening the upper portion of which is herein designated by the reference numeral 116 and is of substantially the same diameter as the opening 113 in the upper portion 115 of the gland end cap, and the lower portion 117 of which provides for the piston rod 108 to extend out therethrough with slight clearance. Disposed in the portion 116 of the central opening in the lower portion 114 of the gland end cap is an annular felt wiper ring 118 which acts as a lint seal.

The cylinder 40 made up of the blind end body 62, the blind end cap 84, the gland end body 64 and the gland end cap 114-115 are ali held together by a plurality of tie rods here shown as four in number extending between the blind end cap 84 and the gland end cap 114. Specifically, the blind end cap 84 is provided with four threaded apertures 120 which receive the threaded ends 122 of four tie rods 124. The tie rods pass through four circular cavities or passages 126 in the blind end body 62 and are disposed outwardly of the central cylindrical portion 60. At the gland end of the cylinder 40 the tie rods 124 again pass through four passages 128 in the gland end body and thence through passages in the gland end cap 114415 to extend therebelow. The exposed bottom ends of the tie rods 124 are threaded to receive nuts 130 which may be tightened up into compressive engagement with gland end cap 114 to pull the entire cylinder assembly 40 into compression to tightly hold the arrangement. Using this tie rod 108 arrangement provides a convenient assembly means for the cylinder 40 as described.

The piston rod 108 from its threaded bottom end 132 to a portion thereof within the space defined by the central cylinder 60 is of substantially constant diameter.

However, within the central cylinder 60 the piston rod is provided with a shoulder 134 leading to a portion of reduced diameter which is disposed within the piston 44 and associated sealing means. Specifically, in abutting relation with the shoulder 134 on the piston rod 108 is a U-cup pedestal 136 of smaller diameter than the cylinder 60 and having an upwardly extending annular portion .138 which is adapted to engage and support a U-cup 140 resting against an abutment 142 on piston 44. The piston 44 itself is divided into three portions, a lower portion 14-4 of outer diameter significantly smaller than the diameter of the cylinder 60 for the accommodation of the U-cup support 136 and U-cup- 140, a central portion 146 in tight sliding relation with the cylinder wall, and an upper portion of reduced diameter 148 again for accommodating a U-cup 150 and a U-cup support 152. The piston rod 108 extends up through registered openings of substantially the same diameter as the piston rod in the U-cup support 136, the piston 44 and the U- cup support 152, and extends outwardly through the U- 'cup support 152 and thereabove where it terminates. For reasons which will become apparent hereinafter, piston rod 108 has a longitudinal passage 1'72 extending the entire length thereof. The passage 172 at the upper end is threaded and has disposed therein the threaded end of a plug 156 which closes passage 172 and serves to compress the components associated with the piston 44 to hold them in relative fixed relation with U-cup supports forcing portions of the U-cups into a sliding sealing fit with the wall of the cylinder 60. Thus, when the piston rod is moved relative to the cylinder, the piston rod, together with the piston 44, the U-cup supports 136 and 152 and their associated U-cups 140 and 150 will all move together and prevent the passage of significant amounts of hydraulic fluid. To insure a. tight fit between the piston rod 108 and piston 44 and its associated U-cup supports 136 and 152, the piston rod 108 is providedwith a plurality of circumferentially extending grooves 185 in which are disposed O-rings 160 which respectively engage the ineriors of the U-cup supports 136 and 152 and of the piston 44. Thus a tight seal is etfected.

As noted at the beginning of the description of the piston-cylinder arrangement illustrated in FIGS. 3, 4 and 5, one of the major features of the structure therein shown is the provision of novel means for permitting the venting of trapped air in the system whereby to render the fiuid therein substantially incompressible without gaseous inclusions. When the piston and cylinder is oriented as shown in FIG. 3 with the blind end body at the top, the air passage 78 and its outlet 80 will serve as a means for bleeding trapped air from the system above the piston 44. That is to say, all air above the piston will tend to rise to the very top of the cavity 70, namely in the portion 76, and can then be bled out through the air passage 78 and its unplugged outlet 80. After air removal, outlet 80 is replugged by plug '82.

Likewise, if the piston and cylinder is oriented in a reversed direction as the pistomcylinder 34 of FIG. 2, for example, then the air above the piston 44 can be vented through the air passage 98 and its outlet 100 which are associated with the U-cup pedestal 104 and the air passages provided therein for communication with air passage 98. Again, after venting the outlet 100 is plugged by threaded plug 102.

However, there are two other points where air will accumulate within the piston and cylinder. Again assuming the orientation shown in FIG. 3, it will be obvious that air trapped below the piston will accumulate at the bottom of the piston 44. In accordance with the present invention, means are provided for venting this air from the bottom of the piston 44 as viewed in FIG. 3. The venting means includes a plurality of longitudinally extending passages in the periphery of the U-cup pedestal 136-, which passages are here shown as four in number and are all designated by the reference numeral 162-, all of which are in communication with the space 90 in the gland end body 64. The upper ends of the passages 162 communicate with notches 164 in the upwardly extending annular portion 138 of the U-cup pedestal 136 which notches in turn communicate with radial passages in the piston itself which passages are designated by the reference numeral 166. The passages 166 lead from the notches 164 in the U-cup pedestal portion 138 to a circumferentially extending groove 168 in piston rod 168. A plurality, here shown as four in number, of radially extending passages 169 lead from the circumferential groove 168 to the central longitudinally extending passage 172 in piston rod 108. Passage 172 extends from the bottom of plug 156 the full length of the piston rod 108. At the lower end, namely the threaded end 132, a connecting member is threadedly secured thereto, which member is designated by the reference numeral 174 and has a central passage 176 which registers with the piston rod passage 172. At the lower end of the passage 176 is a threaded outlet 178 here shown as plugged by a complementary threaded plug 1&0.

Assuming the orientation shown in FIG. 3, air trapped beneath the piston 44 can be forced upwardly through the passages 162, the notches 164 in the U-cup pedestal 138, the radial passages 166 in the piston 44, the circumferential groove 16% in the piston rod, the radial passages 169 in the piston rod, the longitudinally extending air passage 172 in the piston rod 108, the air passage 176 in the connecting member 164-, and out through the then unplugged vent 1'78 whereby to remove the air trapped from the cylinder. After venting, plug 181 is replaced to seal off the system. Thus means are provided for venting trapped air below the cylinder 44 when the piston and cylinder is in the orientation shown in FIG. 3.

If the piston and cylinder is in the reverse orientation as schematically illustrated by the piston and cylinder 34 of FIG. 2, in addition to the air passage 98 now above the piston, means must be provided for venting air trapped below the piston in said reverse orientation. Such means are similar to the means above described involving the U-cup pedestal passages and the piston rod passage. Specifically, longitudinally extending grooves 1.82 are provided in the U-cup pedestal 152 which grooves communicate with notches 184 in the annular longitudinally extending portion of U-cup pedestal 152. The notches 184 communicate with radial passages 186 in the piston 44 which passages in turn communicate with an annular or circumferentially extending groove 18% in the piston rod 108. The circumferential groove 188 in turn communicates with four radially extending passages 190 (in the piston rod 1118 which passages 190 extend between the groove .188 and the longitudinally extending passage 162 in the piston rod 108. Thereafter the air vent passage means is identical to that described above. That is the air vent passage means includes the communicating passage 176 in connecting member 174 and finally the outlet 178.

It will be obvious that both air venting means associated with the piston 44 cannot provide open air passages at the same time because if both were open at the same time, air trapped below the piston could find its way through the passage means to the space above the piston. Thus in the final machining of the piston rod, either the radially extending passages 169 or the radially extending passages 1% in the piston rod 108 are machined through, but never both. Thus in FIG. the passages 190 are shown to be blocked or incomplete as they are not employed with the orientation of the piston and cylinder as shown in FIG. 3. The passages 169 on the other hand are completed to complete the air venting circuit above described. When the piston and cylinder is in its opposite orientation, the passages 169 will be left blocked and the passages 190 will be machined through to open them to provide the venting means above described.

It is desirable to prevent any radial loads from being applied to the piston or piston gland. Such loads can cause undue friction and wear. In the present structure, radial loads are eliminated by securing the cylinder and piston rod to the frame and base of the machine by means of spherical bearings 2G0 and 202. Easy connections of this type may be effected at the end of the frame 14 Where the piston rod extends upwardly and the cylinder extends downwardly, as, for example, end 28 of frame 14 as viewed in FIG. 2. However, on the end 26 of the frame 14 where the piston extends upwardly, the availability of connecting means is rather limited. In FIGS. 1 and 2, this end is end 26. It has been. found that the most convenient way of connecting the piston and cylinder in a position above the frame is to employ a cage-like support means 42 of FIG. 2. In order to achieve this, a mounting plate- 212 (FIGS. 35) is provided for mounting on a bracket 214 fixedly connected to the base 12 of the Schifili embroidery machine. The actual mounting is secured by means of bolts 216. The mounting plate 212 and the bracket 214 are each provided with registered apertures 218 of relatively large diameter as compared with the diameter of the piston rod 163 which passes therethrough whereby to provide clearance for the piston rod relative to the mounting plate 212 and the mounting bracket 214.

r Extending upward from the mounting plate 212 are four support rods 22%) which are connected to plate 212 by bolts 222 and which have a mounting plate 224 resting on their tops. The mounting plate is secured to the support rods by bolts 226.

At the bottom of the mounting plate 224- is a clevis and joint 2%. Thus mounting plate 212, the support rods 220 and the mounting plate 224 yield a cage-like support means 42 for mounting the cylinder to the base 12 notwithstanding the fact that the upper end of the cylinder extends substantially above the frame 14 as may be seen in FIG. 1. It will be obvious that when the piston and cylinder is oriented as the piston and cylinder arrangement 34- of FIG. 2 the cage-like supporting structure 42 is not necessary to effect the mounting to the frame and base. However it will be obvious that with the cage-like structure 42 on the driven end 26 of the frame and with spherical bearing connections to the frame and base of the piston and cylinders at both ends of the frame that there will be no radial loading of the piston rod.

As already noted frame 14 moves both vertically and horizontally in response to moving means 17. In actual Schiffii machines, as is well known, the moving means 17 includes independent means for moving the frame horizontally and vertically which means are arranged in well known manners not to interfere with one another. For example, the input from the horizontal moving means may connect to end 26 of frame 14 through a vertical slot in the frame in which a roller connected to the moving means rides. The vertical movement input means may terminate in a roller 230 on which driven end 26 of the frame 14 rests (FIG. 2).

Regardless of which of the well known means for con meeting the horizontal and vertical movements to the frame are employed, it will be obvious that the control means 30 should not interfere with the horizontal movement. This is most conveniently achieved by connecting the pistons and cylinders 32 and 34 to frame 14 through the vertical movement input means, whatever its form. This will insure the stabilizing of vertical movement of the frame with no interference with horizontal movement thereof.

This is illustrated in FIG. 2 wherein the spherical bearing 202 is connected to the roller 230 as by a connecting link 232 fixed to the area 234 of moving means 17 on which roller 230 is mounted. On the free end as shown in FIG. 2, spherical bearing 202 is fixed to the spindle on which a roller 236 is mounted for connecting the piston rod 54 to the frame 14 so that there will be no interference to horizontal movement of said frame. Other means of connecting piston-cylinders 32 and 34 to rollers 9 230 and 236, respectively, may be employed without departing from this invention.

It will also be obvious that pipelines 36 and 38 should be substantially non-deformable so that, when a pressure pulse surges through the system, the surge is transmitted from cylinder to cylinder and is not absorbed by expansion of the pipelines. Thus, relatively heavy walled pipe should be employed.

While in the schematic drawing of FIG. 2 the connecting means 42 for tying a cylinder extending upwardly above the frame to the base is shown as extending all the way to what might be thought of as the floor, it will be obvious that this is merely a schematic representation. A perusal of FIG. 1 and a rudimentary knowledge of Schiflli embroidery machines will demonstrate that the base 12 extends upwardly from the floor a substantial distance; thus the connecting means 42 need not extend all the way to the floor but merely to some convenient mounting plate on an upper portion of the base 12.

While I have herein shown and described the preferred form of the present invention and have suggested modifications therein, other changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of this invention.

What is claimed is:

1. In combination with a Schifili embroidery machine including a base, an elongated frame for supporting a work piece, embroidery tools, and means for moving said frame relative to said base; means providing for concurrent movement of both ends of said frame comprising a first piston and cylinder, means for connecting one of said first piston and cylinder to one end of said frame and the other of said first piston and cylinder to said base for relatively moving said piston and cylinder in accordance with the movement of said frame, a second piston and cylinder of substantially the same dimensions as said first piston and cylinder, means for connecting one of said second piston and cylinder to the other end of said frame and for connecting the other of said second piston and cylinder to said base for moving said other end of said frame in response to relative movement between said second piston and cylinder, an incompressible fluid filling the unoccupied space in said first and second cylinder, a first pipe line connected to said first cylinder on the side of said first piston containing fluid which resists movement of said one end of said frame in a given direction and connected to said second cylinder on the side of said second piston containing fluid adapted to exert a pressure on said second piston in a direction resulting in movement of said other end of said frame in said given direction, a second pipe line connected to said first and second cylinder on the sides of said first and second pistons opposite the sides thereof to which said first pipe line is connected, and incompressible fiuid filling said first and second pipe lines.

2. The combination of claim 1, further comprising means for venting said cylinders of entrapped gas on both sides of said pistons.

3. The combination of claim 1, wherein said first and second pistons are each connected to a piston rod extending out through said first and second cylinders respectively and longitudinally thereof, and said first pipe line is connected to said first and second cylinders on the sides of said first and second pistons respectively through which said piston rods extend.

4. The combination of claim 1, wherein said means for moving said frame relative to said base moves said frame reciprocally in a vertical direction, the longitudinal axes of said first and second cylinders being substantially vertically oriented, means for connecting one of said first piston and cylinder to said one end of said frame for fixing the two connected elements against relative vertical movement, means for connecting the other of said first piston and cylinder to said base for fixing the two connected elements against relative vertical movement, means 10 for connecting one of said second piston and cylinder to the other end of said frame for fixing the two connected elements against relative vertical movement, and means for connecting the other of said second piston and cylinder to said base for fixing the two connected elements against relative vertical movement.

5. The combination of claim 4, wherein said means for moving said frame relative to said base also moves said frame reciprocally in the horizontal direction, and said four connecting means each include a spherical bearing to prevent radial loading of said pistons and cylinders.

6. The combination of claim 4, wherein said means for fixedly connecting said first and second pistons includes first and second piston rods respectively extending longitudinally of said first and second cylinders and connected to said first and second pistons, and means for venting trapped gas in said first and second cylinders on both sides of said first and second pistons, the means for venting said trapped gas on the lower sides of said pistons including longitudinally extending air passages in each piston rod.

7. In combination with a Schiifi embroidery machine including a base, an elongated frame for supporting a work piece, embroidery tools, and means for vertically reciprocally moving said frame relative to said base, means providing for concurrent movement of both ends of said frame comprising a first expansible chamber units comprising a hollow cylindrical portion, a piston slidably disposed within said hollow cylindrical portion, a blind end body overlying and closing one end of said hollow cylindrical portion, a gland end body overlying the other end of said hollow cylindrical portion and having an aperture therein, a piston rod slidably extending through said aperture and being fixed to said piston, and means for venting entrapped gas within said cylinder including an air passage extending longitudinally through said piston rod to a point outside of said cylinder portion, a pair of opposed U-cups seated on opposite ends of said piston and slidably sealingly engaging said hollow cylindrical portion, and a pair of U-cup pedestals mounted on said piston shaft in engagement with said U-cups with said U-cups sandwiched between said second pedestals and said piston, said venting means further comprising an air passage extending from said longitudinal air passage in said piston rod to the exterior surface thereof, and a communieating air passage defined by one of said U-cup pedestals, said first expansible chamber unit being vertically oriented with said blind end body at the upper end thereof, and said U-cup defining said communicating air passage is the U-cup on the gland end body side of said piston, and said communicating air passage being defined by a longitudinally extending groove in the wall of said last mentioned U-cup and extending from the end thereof closest to said gland end body to the end adjacent the engaging -cup, and a notch in the end of said U-cup pedestal engaging said last mentioned U-cup, means fixing said first cylinder portion to said base against relative vertical movement and said first piston rod to one end of said frame against relative vertical movement, a second expansible chamber units comprising a second hollow cylindrical portion, a second piston slidably disposed within said second hollow cylindrical portion, a second blind end body overlying and closing one end of said second hollow cylindrical portion, a second gland end body overlying the other end of said second hollow cylindrical portion and having an aperture therein, a second piston rod slidably extending through said aperture and being fixed to said second piston, and means for venting said entrapped gas within said second cylinder portion including an air passage extending longitudinally through said second piston rod to a point outside of said second cylinder portion, a second pair of opposed U-cups seated on opposite ends of said second piston and slidably sealingly engaging said second hollow cylindrical portion, and a 1 1 second pair of U-cup pedestals mounted on said second piston shaft in engagement with said second U-cups with said second U-cups sandwiched between said second pedestals and said second piston, said venting means further comprising an air passage extending from said longitudinal air passage in said second piston rod to the exterior surface thereof, and a second communicating air passage defined by one of said second U-cup pedestals, said second expansible chamber unit being vertically oriented with said second gland end body at the upper end thereof, and said second Ucup defining said second communicating air passage is the U-cup on the blind end body side of said second piston, and said second communicating air passage being defined by a longitudinally extending groove in the wall of said last mentioned U-cup and extending from the end thereof closest to said second blind end body to the end adjacent the engaging U-cup, and a notch in the end of said second U-cup pedestal engaging said last mentioned U-cup, means fixing said second piston rod to the other end of said frame against relative vertical movement and said second cylinder portion to said base against relative vertical movement, a first pipe line connecting the portion of said first cylinder portion on the gland end body side of said first piston to the portion of said second cylinder portion on the gland end body side of said second piston, a second pipe line connecting the portion of said first cylinder portion on the 1,2 blind end body side of said first piston to the portion of said second cylinder portion on the blind end body side of said second piston, and an incompressible fluid filling the unoccupied space in said first and second cylinder portions and said first and second pipe lines.

8. The combination of claim 7, wherein said means for fixing said expansible chamber units against vertical movement relative to said frame and base all include a spherical bearing to prevent radial loading of said expansible chamber units between said frame and base.

9. The combination of claim 8 further including a first and a second roller supporting said two ends of said frame for horizontal movement relative to said base, means for connecting one of said rollers to said means for vertically moving said frame, and said means for fixing said first and second piston rods to said frame against relative vertical movement including said first and second rollers.

References Cited UNITED STATES PATENTS 815,177 3/1906 Knecht 112-91 1,086,471 2/1914 Schoenfeld 11291 1,129,607 2/1915 Schoenfeld 112-9l X 1,204,434 11/1916 Hardegger.

JORDAN FRANKLIN, Primary Examiner. A. R. GUEST, Examiner. 

1. IN A COMBINATION WITH A SCHIFFI EMBROIDERY MACHINE INCLUDING A BASE, AN ELONGATED FRAME FOR SUPPORTING A WORK PIECE, EMBROIDERY TOOLS, AND MEANS FOR MOVING SAID FRAME RELATIVE TO SAID BASE; MEANS PROVIDING FOR CONCURRENT MOVEMENT OF BOTH ENDS OF SAID FRAME COMPRISING A FIRST PISTON AND CYLINDER, MEANS FOR CONNECTING ONE OF SAID FIRST PISTON AND CYLINDER TO ONE END OF SAID FRAME AND THE OTHER OF SAID FIRST PISTON AND CYLINDER TO SAID BASE FOR RELATIVELY MOVING SAID PISTON AND CYLINDER IN ACCORDANCE WITH THE MOVEMENT OF SAID FRAME, A SECOND PISTON AND CYLINDER OF SUBSTANTIALLY THE SAME DIMENSIONS AS SAID FIRST PISTON AND CYLINDER, MEANS FOR CONNECTING ONE OF SAID SECOND PISTON AND CYLINDER TO THE OTHER END OF SAID FRAME AND FOR CONNECTING THE OTHER OF SAID SECOND PISTON AND CYLINDER TO SAID BASE FOR MOVING SAID OTHER END OF SAID FRAME IN RESPONSE TO RELATIVE MOVEMENT BETWEEN SAID SECOND PISTON AND CYLINDER, AN INCOMPRRESSIBLE FLUID FILLING THE UNOCCUPIED SPACE IN SAID FIRST AND SECOND CYLINDER, A FIRST PIPE LINE CONNECTED TO SAID FIRST CYLINDER ON THE SIDE OF SAID FIRST PISTON CONTAINING FLUID WHICH RESISTS MOVEMENT OF SAID ONE END OF SAID FRAME IN A GIVEN DIRECTION AND CONNECTED TO SAID SECOND CYLINDER ON THE SIDE OF SAID SECOND PISTON CONTAINING FLUID ADAPTED TO EXERT A PRESSURE ON SAID SECOND PISTON IN A DIRECTION RESULTING IN MOVEMENT OF SAID OTHER END OF SAID FRAME IN SAID GIVEN DIRECTION, A SECOND PIPE LINE CONNECTED TO SAID FIRST AND SECOND CYLINDER ON TH SIDES OF SAID FIRST AND SECOND PISTONS OPPOSITE, THE SIDES THEREOF OF WHICH SAID FIRST PIPE LINE IS CONNECTED, AND INCOMPRESSIBLE FLUID FILLING SAID FIRST AND SECOND PIPE LINES. 